Discussion about El-Nino, La-Nina and tornado outbreak years?

Not to long ago, I had a disscussion about predicting a out break year. And i decided to think deep into the subject. I have been wondering if our Tornado out breaks in the past years, have been related to the phonmenon known as El-Nino and La-Nina. So let begin....

First off... what is the difinition of a tornado outbreak?

Well according to Wikipedia to saids quote.... http://en.wikipedia.org/wiki/Tornado_outbreak


"While there is no single agreed upon definition, generally more than six tornadoes in a day in the same region is considered a tornado outbreak.[1] A series of continuous or near continuous tornado outbreak days is a tornado outbreak sequence"

This could be the first problem. Now i continuted my investigation... I was givin links to numerous reasearch paper and i read them all and still came up with no strong concludion. Now dont get me wrong... there has been many papers writtin about this very subject. Some papers have gotten so deep that even our brightest team member would finish to scratching his head. leaving stuff like mathmatical equations the "guessimates" that even had your own "team forcaster" going ...what????

http://www.coaps.fsu.edu/papers/impacts_enso_tornadic_activity/

Still once you get past the math... It s very good paper. But it seem they are adding to many varibles to such a easy question.. "I will explain later"

Now this next paper tryed to add in not only the strangth but the frequency of tornado activity during El-Nino/ La-Nina years. Once again, a very well done paper, but looking do deep into the main question.

http://ams.allenpress.com/archive/1520-0493/129/4/pdf/i1520-0493-129-4-884.pdf

Now remember, I am not a meterologist, I am self educated, and try to think in a logical manner at all times. So this is how i see it....

The goal.... If tornado outbreaks are indeed related to El-Nino and La-Nina years, then the meterological community would be able to use this as a tool for predicting severe weather for years to come. But to do this it need to be stripped down to the bone. So how do we accomplish such a large task?

First off... we choose a time frame to do this study.... 10 years, 20 years or more.
Second... by using to information givin by the "trained" community, such as touch down counts per storm. Now this could run into one problem... We could have more then one chaser count the same tornado. This would have to be figured out at a later time.

After the data, has been gathered, makeing a graph of tornado counts for that month, and making another graph of outbreak storms for each month. Wow i can feel my brain getting tired for thinking so hard. Now after a few years of data we can start looking at Nutral, Positive and Negitive years and compare data. The key is to find a trend. If one is found this could be a big break through, to unlocking toradic development.

Then we go deeper inthe the study like including the sizes and different wind speed to tornadoes.... Well that was alot and I hope i was not full of hot air. Please dont be afraid to leave your comments. We learn from each other and i learn from you....

I read an article awhile back that included a study by a graduate student from Purdue University. Suzanne Zurn-Birkhimer compared the geographical variation in tornadoes for El Nino years vs. La Nina years during an 81-year-period. Her study showed no reason to expect more or fewer tornadoes overall. But the findings show clear evidence of geographical shifts in tornado activity within the United States when comparing strong El Nino years to La Nina years.
She compared tornado activity during El Nino and La Nina events by calculating a ratio of tornadoes on a state-by-state basis. Her findings show more tornadoes in the central and southern plains and the Gulf Coast during strong El Nino years, with a shift to more tornadoes in the lower Midwest, the Ohio and Tennessee valleys, and the mid-Atlantic region during La Nina years. This study also showed there is little evidence that El Ninos are associated with more or less tornado activity.
La Nina events, however, seem to favor an above-average annual number of tornadoes in select geographical regions. These studies seem to as you say Robert, "go too deep" where others I feel do not go deep enough.

But is it really a simple answer taking into account all of the contributing factors? I would say overall no. It is far more complex due to the fact that the strength of those cycles also are a factor. I think that is where the data starts to get foggy. But the one thing that is showing more consistancy is that while the total number of twisters does not necessarily change overall, the favored location and intensity do seem to shift. Looking at this and the need to predict and forecast tornados. I think predicting geographical locations more favorable for tornado development gets us much closer to the goal of predicting and forecasting tornado development. Another key finding is that tornadoes during a La Nina are stronger and remain on the ground longer than those observed during an El Nino. That means an increased danger of large destructive and deadly tornadoes during the cold phase. There is also an increased risk of "tornado swarms" or outbreaks of 40 or more twisters from a single weather system in a La Nina season. Some researchers believe a recent climate shift favoring a cooler Pacific and more frequent La Nina events suggests we have entered a period of increasing severe storms that could last a decade or more. Yeah for us right?

The main thing that I have taken from this from looking into this is that MI, IL, IN, TX, AR, MS, western TN and western KY are favorable targets during La Nina events where during El-Nino events LA, MS, AL and FL are the more favorable targets.

Interesting...

It's actually quite fascinating and I will look into it more.

ENSO Alert System Status: El Niño Advisory

Outlook:

El Niño is expected to continue strengthening and last through at least the Northern Hemisphere Winter 2009-2010.


During October 2009, sea surface temperature (SST) anomalies increased across the central and eastern equatorial Pacific Ocean. The monthly Niño-3.4 index increased to +1.0°C. Above-average subsurface temperature anomalies increased across a large region of the central and east-central Pacific, with anomalies ranging between +1 to +5°C by the end of the month. Consistent with this warming, subsurface oceanic heat content anomalies (average departures in the upper 300m of the ocean) also increased during the month. In addition, low-level westerly and upper-level easterly wind anomalies strengthened over much of the equatorial Pacific. The pattern of tropical convection also remained consistent with El Niño, with enhanced convection over the west-central Pacific and suppressed convection over Indonesia. Collectively, these oceanic and atmospheric anomalies reflect a strengthening El Niño.



There continues to be disagreement among the models on the eventual strength of El Niño, but the majority indicate that the three-month average Niño-3.4 SST index value will range between +1.0°C and +1.5°C during the Northern Hemisphere winter. Consistent with the historical evolution of El Niño, a peak in SST anomalies is expected during November-January. Presently, there is considerable uncertainty over how long this event will persist. Most of the models suggest El Niño will last through March-May 2010, although the most likely outcome is that it will peak with at least moderate strength (3-month Niño-3.4 SST index of +1.0°C or greater) and last through at least the Northern Hemisphere winter 2009-10.



If this model disscussion holds it could mean that potential target areas for 2010 at least through May could be LA, MS, AL and FL. Based on my previous post. We did see quite a bit of activities in those states already this year.

Ok after doing more digging on this subject I do believe we could see some tornados in the gulf region through May 2010. However the current ENSO Oct-Nov models show the end or severe weakening of the El Nino cycle in May. Then moving into a neutral cycle.
With that, the neutral cycles tend to produce less tornados then during the El Nino and La Nina cycles. So maybe 2010 turns out to be a bigger bust than 2009.
Again I'm focusing on El Nino and La Nina and there are way too many factors to base whether or not tornado outbrakes will or will not happen. I just find it extremly interesting. Could there and will there be some other weather phenomona that will break the norm and increase our chances. Other chasers have predicted a 2010 outbrake as did myself, but is that just may be more wishcasting that actual scientific prediction. I am going to wrestle this bull until I can make a fact based prediction on 2010's season.

https://www.facebook.com/l.php?u=http%3A%2F%2Fams.confex.com%2Fams%2Fpdfpapers%2F141973.pdf&h=7a1b4b4ff1eafee46151f46860684782

I really enjoyed reading this article, it goes into depth about how outbreak #'s don't change in either El Nino or La Nina years, it's just that the location due to the change in the jet's is different. I suggest everyone reading through this... like I said it's really in depth but benificial.

Crap...